Genetically modified DP915635 maize is agronomically and compositionally comparable to non-genetically modified maize.

DP915635 maize was genetically modified (GM) to express the IPD079Ea protein for corn rootworm (Diabrotica spp.) control. DP915635 maize also expresses the phosphinothricin acetyltransferase (PAT) protein for tolerance to glufosinate herbicide and the phosphomannose isomerase (PMI) protein that was used as a selectable marker. A field study was conducted at ten sites in the United States and Canada during the 2019 growing season. Of the 11 agronomic endpoints that were evaluated, two of them (early stand count and days to flowering) were statistically significant compared with the control maize based on unadjusted p-values; however, these differences were not significant after FDR-adjustment of p-values. Composition analytes from DP915635 maize grain and forage (proximates, fiber, minerals, amino acids, fatty acids, vitamins, anti-nutrients, and secondary metabolites) were compared to non-GM near-isoline control maize (control maize) and non-GM commercial maize (reference maize). Statistically significant differences were observed for 7 of the 79 compositional analytes (16:1 palmitoleic acid, 18:0 stearic acid, 18:1 oleic acid, 18:2 linoleic acid, 24:0 lignoceric acid, methionine, and α-tocopherol); however, these differences were not significant after FDR-adjustment. Additionally, all of the values for composition analytes fell within the range of natural variation established from the in-study reference range, literature range, and/or tolerance interval. These results demonstrate that DP915635 is agronomically and compositionally comparable to non-GM maize represented by non-GM near-isoline control maize and non-GM commercial maize.

Transgene expression in sprayed and non-sprayed herbicide-tolerant genetically engineered crops is equivalent.

Regulations governing the safety assessment of genetically engineered (GE) crops require studies that measure the expression levels of the transgene products (proteins and double-stranded RNA) in the GE crop; furthermore, the regulations also often mandate the inclusion of an entry of the GE crop that is sprayed with the herbicide to which tolerance was engineered and a non-sprayed entry of the GE crop in said studies. The hypothesized unique risk of altered transgene expression in response to application of herbicides related to herbicide-tolerant GE crops, compared with application of other herbicides, is not readily apparent. Field studies were conducted with GE maize, soybean, and cotton breeding stacks containing multiple herbicide tolerance traits; studies included plots that were sprayed with the trait-related herbicides and plots that were unsprayed. The GE herbicide-tolerance traits and complimentary herbicides investigated here comprise the majority of those that are currently in commercial use. Transgene product expression was characterized in crop tissues that were collected throughout the growing season. Results confirm the expectation, which is based on the fact that modes of action and regulatory elements in the genetic constructs of the herbicide-tolerance traits are well understood, that applying herbicides associated with GE herbicide-tolerance traits does not meaningfully affect transgene expression. These findings call into question the routine requirement for the inclusion of herbicide sprayed and non-sprayed entries in transgene-expression studies designed to support risk assessment.

Transgene-product expression levels in genetically engineered breeding stacks are equivalent to those of the single events.

Transgene product expression levels are measured in genetically engineered (GE) crops containing single transformation events and the measured expression levels are then utilized in food, feed, and environmental safety assessments as part of the requirements for de-regulation of the event. Many countries also require measurement of expression levels and safety assessments for GE breeding stacks, even though the breeding stacks are composed of single events that have been previously assessed. Transgene product expression levels were measured in tissues of maize, soybean, and cotton breeding stacks and each of their component single events. Expression levels in the breeding stacks were plotted against expression levels in the single events to quantify the ability of the single events to predict transgene product expression levels in the breeding stacks. These results indicate that transgene product expression levels in single events are a reliable indicator of expression levels in breeding stacks. Based on these results it is concluded that safety assessments for breeding stacks can be conducted using transgene product expression levels from single events.

EFSA Genetically Engineered Crop Composition Equivalence Approach: Performance and Consistency.

The European Food Safety Authority (EFSA) oversees the safety assessment of genetically engineered (GE) crops in the European Union and has developed a study design and statistical approach for assessing the compositional equivalency between a GE crop and the corresponding non-GE crop on the basis of the results from a small number of concurrently grown reference lines. Confidence limits around the differences in mean analyte composition between the GE variety and the reference lines are compared with equivalence limits on the basis of the variability of the reference lines. Here, we evaluated the performance and consistency of the equivalence conclusions using a non-GE variety that is, by definition, equivalent to the non-GE crop. Using this approach across the same analytes with the same non-GE variety, it was found that equivalence could not be concluded for 19.7, 22.9, 25.4, and 53.5% of the analytes in four separate studies. In addition, equivalency conclusions for the same analyte often differed from study to study. These results call into question the consistency and value of this approach in the risk assessment of GE crops.

Isoline use in crop composition studies with genetically modified crops under EFSA guidance - Short communication.

The European Food Safety Authority (EFSA) oversees the safety evaluation of genetically modified (GM) crops in the European Union. EFSA requires inclusion of commercial non-GM reference lines and a non-GM isoline in crop composition studies with GM crops. Reference lines are used to construct equivalence limits for each compositional analyte. Results for the GM line are compared with these equivalence limits to assess compositional equivalence between the GM crop and the non-GM crop. If compositional equivalence cannot be concluded from this comparison, then results for the non-GM isoline can be used to determine if this finding is likely the result of the background non-GM genetics of the GM crop. If this latter comparison is not sufficient to assess the compositional safety of the GM crop, then a biological-relevance assessment for the analytes in question can be completed taking into account the greater body of knowledge of composition for the crop and diets. Thus, the isoline is a useful comparator but not required to assess the compositional safety of the GM crop, and therefore, unavoidable genotype differences between the isoline and GM line should not be grounds for rejection of compositional studies where the biological relevance of potential non-equivalence is addressed.

Food and feed safety of DAS-444Ø6-6 herbicide-tolerant soybean.

DAS-444Ø6-6 soybean was genetically engineered (GE) to withstand applications of three different herbicides. Tolerance to glufosinate and glyphosate is achieved through expression of the phosphinothricin acetyltransferase (PAT) and double-mutated maize 5-enolpyruvyl shikimate-3-phosphate synthase (2mEPSPS) enzymes, respectively. These proteins are expressed in currently commercialized crops and represent no novel risk. Tolerance to 2,4-dichlorophenoxyacetic acid (2,4-D) is achieved through expression of the aryloxyalkanoate dioxygenase 12 (AAD-12) enzyme, which is novel in crops. The safety of the AAD-12 protein and DAS-444Ø6-6 event was assessed for food and feed safety based on the weight of evidence and found to be as safe as non-GE soybean.

Single-Event Transgene Product Levels Predict Levels in Genetically Modified Breeding Stacks.

The concentration of transgene products (proteins and double-stranded RNA) in genetically modified (GM) crop tissues is measured to support food, feed, and environmental risk assessments. Measurement of transgene product concentrations in breeding stacks of previously assessed and approved GM events is required by many regulatory authorities to evaluate unexpected transgene interactions that might affect expression. Research was conducted to determine how well concentrations of transgene products in single GM events predict levels in breeding stacks composed of these events. The concentrations of transgene products were compared between GM maize, soybean, and cotton breeding stacks (MON-87427 × MON-89034 × DAS-Ø15Ø7-1 × MON-87411 × DAS-59122-7 × DAS-40278-9 corn, DAS-81419-2 × DAS-44406-6 soybean, and DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 × MON-88913-8 × DAS-81910-7 cotton) and their component single events (MON-87427, MON-89034, DAS-Ø15Ø7-1, MON-87411, DAS-59122-7, and DAS-40278-9 corn, DAS-81419-2, and DAS-44406-6 soybean, and DAS-21023-5, DAS-24236-5, SYN-IR102-7, MON-88913-8, and DAS-81910-7 cotton). Comparisons were made within a crop and transgene product across plant tissue types and were also made across transgene products in each breeding stack for grain/seed. Scatter plots were generated comparing expression in the stacks to their component events, and the percent of variability accounted for by the line of identity (y = x) was calculated (coefficient of identity, I2). Results support transgene concentrations in single events predicting similar concentrations in breeding stacks containing the single events. Therefore, food, feed, and environmental risk assessments based on concentrations of transgene products in single GM events are generally applicable to breeding stacks composed of these events.

Transgenesis affects endogenous soybean allergen levels less than traditional breeding.

The regulatory body that oversees the safety assessment of genetically modified (GM) crops in the European Union, the European Food Safety Authority (EFSA), uniquely requires that endogenous allergen levels be quantified as part of the compositional characterization of GM versions of crops, such as soybean, that are considered to be major allergenic foods. The value of this requirement for assessing food safety has been challenged for multiple reasons including negligible risk of altering allergen levels compared with traditional non-GM breeding. Scatter plots comparing the mean endogenous allergen levels in non-GM soybean isoline grain with the respective levels in GM grain or concurrently grown non-GM commercial reference varieties clearly show that transgenesis causes less change compared with traditional breeding. This visual assessment is confirmed by the quantitative fit of the line of identity (y = x) to the datasets. The current science on allergy does not support the requirement for quantifying allergen levels in GM crops to support safety assessment.

Agronomic performance of insect-protected and herbicide-tolerant MON 89034 × TC1507 × NK603 × DAS-40278-9 corn is equivalent to that of conventional corn.

Agronomic characteristics of genetically modified (GM) MON 89034 × TC1507 × NK603 × DAS-40278-9 (PowerCore™ Enlist™), MON 89034 × TC1507 × NK603 (PowerCore™), and DAS-40278-9 (Enlist™) corn, a non-GM near-isogenic hybrid, and 2 commercial non-GM hybrids were assessed in a field study to determine if the agronomic performance of the GM corn hybrids is equivalent to that of non-transgenic hybrid corn. The MON 89034 × TC1507 × NK603 × DAS-40278-9 hybrid corn was developed through stacking of 4 individual transgenic events, MON 89034, TC1507, NK603, and DAS-40278-9 by traditional breeding and contains the cry1A.105 and cry2Ab2 (MON 89034), cry1F and pat (TC1507), cp4 epsps (NK603) and aad-1 (DAS-40278-9) transgenes. These transgenes encode the proteins Cry1A.105, Cry2Ab2, and Cry1F, which confer insect resistance, PAT, CP4 EPSPS, and AAD-1, which confer herbicide tolerance. The following agronomic characteristics were assessed in the study: initial and final stand count, seedling vigor, time to silk, time to pollen shed, pollen viability, plant height, ear height, stalk lodging, root lodging, days to maturity, stay green, disease incidence, insect damage, herbicide injury, and yield. The agronomic assessment was conducted in 2 regions of Brazil (Indianopolis-MG; Cravinhos-SP). The agronomic attributes for all GM entries were statistically indistinguishable from the non-GM near-isogenic hybrid. In addition, most of the agronomic assessments fell within the range of the commercial varieties included in the study. Taken together, MON 89034 × TC1507 × NK603 × DAS-40278, MON 89034 × TC1507 × NK603, and DAS-40278-9 were found to be agronomically equivalent to non-GM corn.

Stacking transgenic event DAS-Ø15Ø7-1 alters maize composition less than traditional breeding.

The impact of crossing ('stacking') genetically modified (GM) events on maize-grain biochemical composition was compared with the impact of generating nonGM hybrids. The compositional similarity of seven GM stacks containing event DAS-Ø15Ø7-1, and their matched nonGM near-isogenic hybrids (iso-hybrids) was compared with the compositional similarity of concurrently grown nonGM hybrids and these same iso-hybrids. Scatter plots were used to visualize comparisons among hybrids and a coefficient of identity (per cent of variation explained by line of identity) was calculated to quantify the relationships within analyte profiles. The composition of GM breeding stacks was more similar to the composition of iso-hybrids than was the composition of nonGM hybrids. NonGM breeding more strongly influenced crop composition than did transgenesis or stacking of GM events. These findings call into question the value of uniquely requiring composition studies for GM crops, especially for breeding stacks composed of GM events previously found to be compositionally normal.

Event DAS-444Ø6-6 soybean grown in Brazil is compositionally equivalent to non-transgenic soybean.

Soybean event DAS-444Ø6-6 is tolerant to the herbicides 2,4-D, glyphosate, and glufosinate. An investigation of potential unintended adverse compositional changes in a genetically modified crop is required to meet government regulatory requirements in various geographies. A study to meet these requirements in Brazil was completed demonstrating compositional equivalency between DAS-444Ø6-6 and non-transgenic soybean. This study supplements the extensive literature supporting transgenesis as less disruptive of crop composition compared with traditional breeding methods.

Insect-protected event DAS-81419-2 soybean (Glycine max L.) grown in the United States and Brazil is compositionally equivalent to nontransgenic soybean.

The transgenic soybean event DAS-81419-2 contains genes that encode the Cry1F, Cry1Ac, and PAT proteins. Cry1F and Cry1Ac provide protection against key lepidopteran insect pests, while PAT confers tolerance to the herbicide glufosinate. To satisfy regulatory requirements for the safety evaluation of transgenic crops, studies were conducted in the United States and Brazil to evaluate the nutrient and antinutrient composition of event DAS-81419-2 soybean. On the basis of the results of these studies, event DAS-81419-2 soybean is compositionally equivalent to nontransgenic soybean. This conclusion concurs with numerous other published studies in soybean and other crops where compositional equivalence between the transgenic crop and its nontransgenic comparator has been demonstrated.

Compositional safety of herbicide-tolerant DAS-81910-7 cotton.

DAS-81910-7 cotton is a transgenic event that was transformed to contain the aad-12 and pat genes. These genes code for the AAD-12 and PAT proteins, which confer tolerance to the herbicides 2,4-D and glufosinate, respectively. Crop composition studies were conducted with DAS-81910-7 cotton (both nonsprayed and sprayed with 2,4-D and glufosinate) to comply with requirements of regulatory authorities responsible for evaluating crop safety. Results indicate compositional equivalence between DAS-81910-7 cottonseed and nontransgenic cottonseed and between sprayed and nonsprayed DAS-81910-7 cottonseed. This study builds on the results from many prior studies which support the conclusion that transgenesis is less likely to unexpectedly alter the composition of crops as compared with traditional breeding.

Aminopyralid soil residues affect rotational vegetable crops in Florida.

BACKGROUND: Bahiagrass (Paspalum notatum Flueggé) is a poor host of several soilborne pests of vegetable crops; therefore vegetable crops are commonly grown in a rotation with bahiagrass pastures in Florida. The herbicide aminopyralid provides foliar and soil residual weed control and increases forage production in bahiagrass pastures; however, the soil residual activity of aminopyralid makes carryover injury likely in subsequent sensitive vegetable crops. Field research was conducted to determine the sensitivity of five vegetable crops to soil residues of aminopyralid. RESULTS: At an aminopyralid soil concentration of 0.2 µg kg(-1) (the limit of quantitation for aminopyralid in this research), crop injury ratings were 48% (bell pepper), 67% (eggplant), 71% (tomato), 3% (muskmelon) and 3% (watermelon), and fruit yield losses (relative to the untreated control) at that concentration were 61, 64, 95, 8 and 14% in those respective crops. CONCLUSIONS: The crops included in this research were negatively affected by aminopyralid at soil concentrations less than the limit of quantitation (0.2 µg kg(-1) ). Therefore, it was concluded that a field bioassay must be used to determine whether carryover injury will occur when these crops are planted on a site where aminopyralid has been previously applied.

Compositional safety of event DAS-40278-9 (AAD-1) herbicide-tolerant maize.

Event DAS-40278-9 maize expresses the aryloxyalkanoate dioxygenase-1 enzyme, which was originally identified in the soil bacterium Sphingobium herbicidovorans. This enzyme degrades 2,4-dichlorophenoxyacetic acid (2,4-D) and aryloxyphenoxypropionate herbicides (e.g., haloxyfop, cyhalofop, quizalofop, etc.); therefore, plants that contain this enzyme are tolerant to these herbicides. We employed the substantial equivalence approach to investigate the compositional safety of event DAS-40278-9 maize. A total of 82 different compositional analyses were conducted to evaluate the equivalence of event DAS-40278-9 and conventional maize. Analyte levels within the transgenic entries were either within literature ranges for non-transgenic maize or statistically indistinguishable from the non-transgenic near-isogenic hybrid, thus indicating substantial equivalence between event DAS-40278-9 and its conventional counterpart. These results agree with dozens of published studies for other transgenic events where input traits were found to have a negligible effect on crop composition compared with traditional breeding methods.